Patent Application
20200283920
Not applicable
Not applicable
The present process invention in continuation to the U.S. Ser. No. 14/392,066 performs the enhancement of CO2 concentration in the CO2-Stream for both, post-combustion as well as pre-combustion carbon capture, which results to number of advantageous features associated with the processing i.e. lowering the production costs to obtain the liquid carbon dioxide from CO2-rich gas stream for the compression, cooling, and the CO2 condensation at one hand, while reduction in the investment for the number and the size of equipment due significantly lower gas flow rate at the other hand (v.i. in the tables in the embodiments with respect to CO2-constituent of the CO2-Stream upstream of CO2-CC as well as the gas flow rates therein).
The post-combustion embodiment of the present invention presents the Advanced Combustion of fossil fuels that encompasses the pretreatment and CO2-enrichment of the CO2-Stream for the advantageous carbon-rich fossil power plants from the petcoke in the first priority, followed with most important fuel for this process, the coal in every grade, then crude oil, following with bio-mass, as well as the waste-to-energy, waste-to-hydrocarbons plants and the natural gas in CHP combined heat and power generation plants, yet more importantly for the gas turbine single or combined cycle plants. This process applies also to other CO2-emitting plants (the Stationary CO2 Sources) like the Black Liquor firing in the Recovery Boiler of pulp and paper industry. Therefore the present process aims at specifically these two major fossil energy power plants in the first place, i.e. coal power plants and the gas turbine single cycle or combined cycle power plants.
The present process invention inyroduces also the Advanced Combustion, wherein the nitrogen-rich air as combustion gas is no longer employed for combustion of fossil fuels.
The Advanced Combustion for the post-combustion carbon capture embodiment according to the present invention is further distinguished;
The characteristic thermodynamic features from the flue gas side are:
Therefore, from the flue gas thermodynamics point of view, the present Advanced Combustion presents with flue gas and flue gas oxy-fueling in the fossil fuel fired power plants a semi-closed, variant of the First Ericson Cycle integrated into the classic Rankin Cycle.
Likewise in the gas turbine plants and from the thermodynamics point of view, the present Advanced Combustion with the semi-closed flue gas and flue gas oxy-fueling, the present patent presents a variant of the First Ericson Cycle integrated into the classic Brayton Cycle.
From the heat recovery side, the thermodynamics of the combination of the classic Rankin Cycle (with steam as the working fluid) together with the First Bairamijamal Cycle (with the carbon dioxide as working fluid) leads to a Dual-Combined Cycle, wherein the heat recovery for power generation reaches out to a gross thermal efficiency in the margin of 65% to 75%.
If the Advanced Combustion is integrated in a new gas turbine power plant (or an existing gas turbine single cycle upgraded to combined cycle), the parent patent's First Bairamijamal Cycle with the working fluid carbon dioxide combined with the balanced heat recovery with the steam as working fluid together in a new heat recovery presents a gas turbine Triple-Combined Cycles with gross thermal efficiency in the margin of 80% to 85% with reference to the most advanced GE 9HA Class gas turbine.
The Advanced Combustion for the pre-combustion embodiment of present invention for primary CO2-Stream from the gasification process and for the secondary syngas of the HPLTE-SG past water-shift converter(s) implies the following six new specific features;
The CO2-Stream from the gasification process comprises the low pressure, intermediate pressure, and most importantly the high pressure gasification of all kind of carbonaciuous feedstock, most significantly coal, petrolium coke, and carbon-rich waste materials as outlined in the U.S. Ser. No. 14/392,066.
The presentation of the state-of-the-art is compiled with reference to U.S. Ser. No. 14/392,066 for the Stationary Sources of CO2 emission.
The other three presently applied technologies for capture of carbon dioxide and re-use of CO2 as new fossil energy resource are the ExxonMobil Air Vacuumig in [1] and Carbon Engineering that takes in the air CO2 for their process [2]. These two latter technologies employ carbon dioxide from the air at the concentration of 0.04 Vol %, thus leading to unimaginable large size of plants if ever feasible for midsize or large scale commercial operation. As Carbon Engineering states, the costs of carbon capture reaches to $100.- per tons of captured carbon dioxide, leading to a predicted production costs of $4.- gasoline a gallon on site. Considering the logistics, distribution and taxes, this might lead to a gasoline price of $5.- to $6.- a gallon while the current gasoline price is posted out at less as $3.- a gallon in North East USA.
The fourth state-of-the-art references to the Carbon Recycling International plant in Island, commonly known as George Olah Plant that utilizes the geothermal carbon dioxide with high CO2 concentration at ca. 95 Vol %, albeight with extremely low CO2 stream in terms of mass flow rate available [3]. The George Olah plant demonstrates the production of high end products from CO2 at high yield and economic feasibility, yet then it faces restrains in terms of commercially viable solution due to very low geothermal gas flow. For instance, the geothermal energy contributes only to ca. 0.2% of US energy consumption in the United States.
Although the current state-of-the-art technologies via [1], [2] and [3] do not take on the major sources of CO2 emission, all these four processes however, eventually comprise carbon capture and conversion of the captured carbon dioxide to high value products, specifically transportation fuels.
The present patent in continuation refers to the state-of-the-art, as outlined for the pre-combustion carbon capture in the parent patent for the CO2-Stream and presented in
The present patent in continuation refers also to the state-of-the-art, as distinguished for the post-combustion carbon capture of the Stationary Sources of CO2 emission in the parent patent for the CO2-Stream U.S. Ser. No. 14/392,066 that has been presented in
The post-combustion carbon capture's primary focus of the present patent in continuation embraces the huge CO2 emission from the Stationary Sources of CO2 emission. For instance, the current U.S. energy cosumption of ca. 86.3% stems in one or other way from the fossil energy carbonacuous resources i.e. coal, petrolium, natural gas, biomass, and waste-to-energy.
The post-combustion carbon capture encompasses also the majority of US power generation that is operational from the CO2 emitting fossil energy. According to EIA report for 2019, 64.8% of electricity is generated by use of fossil resources i.e. from coal, natural gas, petrolium products biomass and municipal waste to energy in the United States [4].
For this reason, the present process invention in continuation presents the embodiment of the invention with reference to the two major kind of fossil power plants without any limitation for other embodiments, i.e. for coal power plant and for the gas turbine power plants, the latter applicable for both for GT single cycle and GT combined cycle.
The current situation in the carbon capture from post-combustion CO2-Streams in U.S. Ser. No. 14/392,066, specifically the flue gas of fossil power plants, is encountered with very low concentration of carbon dioxide in the flue gas, because the current practice of fossil fuel combustion utilizes air as the source of oxygen with only 21 O2 Vol % for the combustion. The low CO2 concentration stems predominantly from the nitrogen constituent of air of ca. 78.5 N2 Vol %. Since the air oxygen lies in the margin of ca. 21 Vol %, the conventional combustion of the fossil fuel in the combustion section is encumbered with the large portion of useless nitrogen. At the other hand, the relatively low concentration of oxygen from the air compels to use more intake air in order to keep an excess oxygen in the flue gas, which in turn promotes a more effective combustion, albeit to more adversse nitrogen to the combustion, ergo more in the flue gas.
The low concentration of the carbon dioxide leads inevitably to very high flue gas flux that leads to more extensive processing in terms of operation costs as well as to larger size of the equipment, particularily expensive compressor, followed by the size of heat exchangers. For instance, the low CO2 concentration at high gas flow in the U.S. Ser. No. 14/392,066 requires more compressors in number as well as in larger size to deal with.
The condensation of CO2 out of a dilute CO2-Stream requires also lower operation temperature in the CO2-CC that in turn increases the operation costs significantly.
These disadvantageous points in the U.S. Ser. No. 14/392,066 could be resolved by introduction of Advanced Combustion, which delivers for U.S. Ser. No. 14/392,066 a very high concentrated CO2-rich CO2-Stream at low gas flow rate. Both factors lead to number of extraordinary advantages, both in processing for low operation costs as well in investment of the plants.
The Advanced Combustion according to the present patent in continuation comprises the use of abundant oxygen obtained from the HPLTE-SG now that would had been released utmost into the atmosphere due to huge surplus, way more than the demand could ever absorb.
The result of the Advanced Combustion in this patent in continuation is best represented in the tables 2 and 3 to each embodiment at a glance.
Given the 92 Vol % CO2 concentration in the flue gas of a coal power plant and to 80 Vol % CO2 in the flue gas of a gas turbine plant the CO2-Stream sets out on comparison with the air 0.041 Vol % CO2, the present Advanced Combustion presents the capability of more than two thousands times more concentrated CO2 in the CO2-Stream for the further processing.
The gas flow rate of the CO2-Stream of a coal power plant can be reduced up to 27% of the CO2-Stream obtained from the conventional combustion (vide Table 1 and Stream 17 in the Table 2). The flow rate of CO2-Stream in the gas turbine reaches to around 6% of conventional combustion in flow rate. These results could be inventive resolved for the post-combustion embodiment by the following specific features, which are collectively introduced as Advanced Combustion, i.e.:
As result of (1), (2) and (3), there is:
The field of the present patent in continuation concerns with Advanced Combustion that supports the technological solution to the global warming and Climate Change presented in the parent patent U.S. Ser. No. 14/392,066.
In pursuant to the advancement of Clean Energy, the present patent in continuation comprises the pre-combustion as well post-combustion carbon dioxide capture in all Stationary Sources of CO2 emission, thus it encompasses the major Green House Gas emitting sources to the degree that other emissions like from vehicle, jet planes, commercial and residential sources can be then readily addressed by the nature soon.
The present patent in continuation supports all other sections of the parent patent, i.e. it comprises the recovery of the useless waste heat released currently into the atmosphere (which heats the globe directly) via operation of CO2-HR section, the conversion of the recovered waste heat to useful energy by operation of the First Bairamijamal Thermodynamic Cycle in CO2-PG, which supplies the utmost portion of the necessary energy for carbon capture in CO2-Stream, and CO2-CC section. Most importantly the First Thermodynamic Cycle generates to the great extent the AC power in the CO2-PG that backs up the HPLTE-SG electrolysis in addition to the multi-stage oxygen and syngas expander turbines after the AC/DC converter (
The present patent in continuation also forges ahead in more straight way to the new generation of power plants, referred to in the parent patent as super-efficient hydrogen based fossil power generation with H2/O2 torches for Direct Steam generation and re-superheating of steam according to the Second Bairamijamal Cycle described therein.
The embodiment of Advanced Combustion is outlied for each three embodiments individually, because of the distinguishing differences and similarities in each embodiment.
Elaborations and further connections to the sections and embodiments of the parent patent are provided in the section for the abbreviations, special technical expressions and terms at the end of present patent in continuation.
The detail description for each embodiment includes the start up period and transient period, in an existing fossil energy plant, wherein the implementation of the Advanced Combustion and the integration of the parent patent is considered up to new normal mode of operation with the associated process control architecture.
The present invention provides more specific information to the parent patent process invention, to which the CO2-Stream is distinguished with high CO2 concentration at very low flow rate. The distinctive specifics of this CO2-Stream comprises it's characteristics from the onset of the plant operation, i.e. from the cold start (“the Black Start”) period of the plant, then up to the full load plant capacity, whereas the CO2-Stream undergoes peculiar treatment in the preparation CO2-rich CO2-Stream upstream to the CO2-CC section, as well as how the CO2-Stream is utilized as a carrier gas for the combustion after oxygen is added to.
This peculiarity of the CO2-Stream in the present process invention is conceived of for the post-combustion purpose in a way, wherein the intake air for combustion is entirely replaced by oxygen-added recirculated CO2-Stream back to the intake and combustion section (referred to flue gas oxy-fueling). By this processing of CO2-Stream, the adverse impacts caused by concommitent nitrogen from the intake air in the existing operational plants in is eliminated totally.
These particular features of the CO2-Stream are presented here for two CO2-Streams in the post-combustion carbon capture and condensation, as well as in one pre-combustion carbon capture and condensation. These three peculiar features of the CO2-Stream are specifically addressed to the existing plants and/or future fossil energy plants, i.e. for:
The description and points of references in the content of the present process invention to the CO2-Stream are associated with the three embodiments (I), (II) and (III) that is more disclosed in the following three embodiments.
In this embodiment, the detailed description of the present process invention is encompassed for the integration of CO2-Stream, pretreatment of the CO2-Stream in the coal, oil, natural gas, biomass fired power plants as well as Black Liquor combustion in the Recovery Boiler and the Bark Boiler firing of the pulp and paper too.
This present embodiment (I) references to the post-combustion carbon capture, which has been previously disclosed in part, inherently in the
One of the pertinent block diagrams for this patent in continuation relates to the block diagram in
The other pertinent block diagram for this more detail disclosure relates to the block diagram in
The embodiment (I) comprises the following six specific features and steps from the cold start of the plant, then up to the normal mode of operation at full load including the intermittent de-sooting procedure, i.e.:
The Advanced Combustion with the flue gas recirculation and flue gas oxy-fueling for the CO2 enrichment in post-combustion CO2-Streams of fossil fuel fired power plants upstream of the CO2-CC section is presented by the brief description and
The
The CO2-Stream 12, presented as CO2-lean gas under the currently operational plants, is the subject of the present patent in continuation as it pertains to the detail processing for the above mentioned eight specific features in the Advanced Combustion. A typical coal power plant ramps up with ca. 5% to 10% of coal load 1 with nearly full load of intake combustion air 2.
It shall be highlighted that the integration of parent patent and the present patent in continuation implies the existence of a water storage tank according to the water codes for DEMIN water at an existing site as usual. A new smaller size intermediary tank for pretreated DEMIN water according to the applicable standards for the electrolysis as an interim tank is considered, as well as few new high-pressure storage tanks for the liquid CO2 at the boundary limit of the plant that is required for the implementation of the Advanced Combustion. Hence this, the ramp up of the plant with the integration of parent patent and present patent presumes the operation of HPLTE-SG that is fed by the liquid carbon dioxide and water from those storage tanks with power supply from the grid at the initial phase of start up. Due to this circumstance, the downstream adjacent plant for high-value products can commence the operation with the syngas already from HPLTE-SG, while the necessary oxygen for the start up is supplied from HPLTE-SG via stream 4 to the power plant.
For this reason, the initial stage of the start-up period is carried out with intake air first. Hence this, the hot flue gas 12 with still abundant portion of nitrogen can be cleaned from the residual aerosol, soot, pollutants, NOx and SOx and other harmful constituent in the parent patent's scrubber 8 (depicted in the
The cold end flue gas 13 downstream of the scrubber 8 is utmost recirculated 15, first via the partially OPEN XV-1 and nearly CLOSED PV-2 to the flue gas recirculation blower 10, then routing the flue gas back to the combustion chamber, wherein the recirculated flue gas 16 is preheated by a heat exchanger or rather than by direct firing of natural gas with the portion of oxygen (from the HPLTE-SG) in the supplementary firing 18. The pure oxygen 4 from the HPLTE-SG section is added to the preheated recirculated flue gas before passing through the CO-oxidation reactor 20, thus termed flue gas oxy-fueling with an oxygen content, set to meet preferably 25% to 40% oxygen by volume via QIC-1 upstream of the combustion chamber of the firing 5. Other oxygen containing residual gases 3, most importantly the oxygen-rich CO2-containing gas downstream of the CO2-CC section, more preferably the re-gasified LOX is also re-routed back to the firing section.
By this way, the initial intake combustion air 2 through PV-1 can be reduced gradually in relative fast pace, while the residual nitrogen is purged by stream 14 through PV-2 to the chimney 9 out of the recirculating flue gas. The first over-ride control circuit via PIC-1, PV-1 and PV-3 directs the transient process control until the smooth transition is completed. The progress can be observed with declining nitrogen via QI-1. By then, the first over-ride control loop CLOSES the PV-1, vide infra.
Depending on the size of HRSG, it takes traditionally two to three more hours by an now increasing coal load from the initial load to 20% coal like in a 500 MW coal power plant until the nitrogen is purged out entirely. After “No Nitrogen” observed by QI-1, the second over-ride control loop takes effect by CLOSING PV-2 and OPENING of PV-4, while the CO2-Stream compressor (
Under the initial start-up and then in normal mode of operation, the residual off gas downstream of the CO2-CC section (i.e. stream 44 downstream of the off gas expander 9 in
The oxygen rich off gas downstream of the CO2 absorber at a pressure close to the CO2-CC pressure is chilled down and dehydrated, by then undergoes an isenthalpic expansion, wherefrom a LOX stream is obtained and a GOX stream encumbered with the inert non-condensable (of coal orgin) components are released into the atmosphere. That LOX undergoes a regasification with the available thermal waste energy e.g. in CO2-HR section, and rerouted back to the combustion, figuratively presented with the stream 3.
The non-condensable gases in the GOX (like from the nitrogen constituent of coal) will be purged downstream of CO2-CC section from the oxygen-rich GOX.
The detailed description of present process invention discloses the integration of CO2-Stream, pretreatment of the CO2-Stream, preparation of CO2-lean flue gas to CO2-rich flue gas from the gas turbine power generation plants, i.e. the gas turbine single cycle plants as well as gas turbine combined cycle power plants.
This detail disclosure references to the post-combustion carbon capture, which has been disclosed in part in the
The post-combustion carbon capture in present patent in continuation references also to the
One of the pertinent block diagram for the description in embodiment (II) relates to the block diagram, presented in
The other pertinent block diagram for this present patent in continuation relates to the block diagram presented in
The embodiment (II) comprises the following seven specific features of the Advanced Combustion and steps from the start up of the gas turbine power plant, then up to the normal mode of operation at 100% load in the processing, including the augmentation case and de-sooting procedure, i.e.:
The Advanced Combustion with flue gas recirculation and flue gas oxy-fueling for the CO2 enrichment in post-combustion CO2-Streams in the flue gas of gas turbine power plants upstream of the CO2-CC section is presented by the brief description and
The
For this purpose, the plant shall start first with the initial startup load of the natural gas 10 and the intake air 11 at the minimal load case with the adjustable blades 1A CLOSED as usual. The intake air 11 is compressed in 1, routed to the combustion chamber 2, wherein the natural gas 10 is added to and ignition takes place. The hot gas is routed then to the turbine compartment 3 that runs the generator. The hot flue gas 15 post turbine compartment is routed to the HRSG 4 in the gas turbine combined cycle plant, wherein steam is generated to run the steam turbine (not depicted in the
After the present process invention implemented in the gas turbine combined cycle plant, the hot flue gas 18 post HRSG 4 will be routed first to the scrubber 5 (i.e. the equipment 5 in the
The recirculated CO2-Stream 22 downstream of the blower 7 is first passed entirely through PV-3 OPEN position, while PV-4 stays still CLOSED. At the initial start up period, the entire oxygen 14 to the gas turbine at the initial minimal load with the CLOSED adjustable blades 1A, is supplied from the CO2 liquid storage tank and the water storage tank over the electrolysis in the HPLTE-SG. These storage tanks supply the first units of HPLTE-SG that feeds back with the needed oxygen for flue gas oxy-fueling through the line 14 and QV-1 in the initial period of operation.
The recirculated flue gas 22 is added with the oxygen by line 14, which may be adjusted in temperature by a heat exchanger or more preferably by H2/O2-torch in normal mode of operation (fed with NG/O2 during the start up period) 27 up the desired reaction temperature required in stream 17 for the CO-oxidation in 8. During the start up period the valve PV-4 is CLOSED, thus the line 16 does not by-pass portion of the recirculated flue gas to the HRSG.
Downstream of the CO-oxidation reactor the temperature of the recirculated flue gas 24 will be lowered to the degree compatible to the permissible intake temperature of the compressor 1 by injection of LOX (e.g. from the GOX expansion post the CO2-absorber and dehydration).
Because the valve PV-4 is CLOSED for the by-pass flue gas 16 to the HRSG 4 during the ramp up period, the compressor 1 operates with the designated intake load gas flow 26 (i.e. streams of 11+24+25) in the start up period.
The permissible gas intake temperature is controlled by the LOX line 25 and the TV1-1 primarily, controlled by TIC-1 in the desuperheater 9. If the maximum permissible intake temperature can not be reached due the available balance of LOX, additional liquid CO2 shall be injected additionally by TV1-2 via line 13 if needed for an existing gas turbine.
Typically, under the minimal load case of the gas turbine and the size of the HRSG, the nitrogen constituent of the flue gas should have declined to near zero as a result of gradually CLOSING intake air valve PV-1 for 11, and the purging the nitrogen via line 20 trough PV-2 in to the stack within a margin of time for two to four hours (observed with the gas analyzer QI-1).
Once the nitrogen constituent of the flue gas QI-1 declines to zero, the first over-ride control loop can be activated, wherein the PV-1 and PV-2 will be CLOSED gradually, XV-1 sets in full OPEN position, while the recirculation of the flue gas 16 into the HRSG can be commenced via OPENING of the PV-4 now. This side stream 16 is necessary in an existing plant, because the integration of the present process invention leads to about 30% to 35% less intake gas through the compressor 1. As result of this, portion of the recirculated CO2-Stream 16 must be routed to the HRSG after it is superheated by a supplementary firing with O2/H2 torch 27 in the normal mode of operation. In the commencing period, the torch(es) are fed with the natural gas and pure oxygen from the HPLTE-SG. By this way, the side stream 16 (typically about 30% of the recirculated flue gas) can be adjusted with the hot gas temperature from the gas turbine 15 in order to balance out the required gas flux 17 impinged to the existing HRSG 4 in the margin of the temperature as before the integration of Advanced Combustion. Once the plant stabilized, the torch(es) 27 can be fed with H2/O2 gases from the HPLTE-SG.
In a new plant, there is no side stream 16 necessary due the compact design of the plant for the same gross output. The gas intake flow 26 to the compressor 1 for the new plants is typically reduced to about 30% that serves to more power shift to the turbine 3, thus it delivers more electricity from the generator.
Traditionally, depending on the size of the HRSG, at this window of time, there is 80 Vol % to 90 Vol % CO2 with the residual oxygen in the margin of 20 Vol % to 10 Vol % in the stream 19, respectively also in the streams 21, and 22. At this juncture, the second over-ride control loop can be activated, whereas the control valve PV-5 OPENS the CO2-rich CO2-Stream 23 to the CO2-Stream's compressor in the CO2-CC section. By then, the further gradual increase of load can be continued until the full load of the gas turbine and the steam turbine of the HRSG.
Under increasing load of the gas turbine, other oxygen-rich process intern streams 12 like that from the CO2-CC section (i.e. streams 43 and 44 of the
The non-condensable gases (like from the traces of nitrogen that would concentrate in the flue gas recirculation) will be purged downstream of CO2-CC section from the oxygen-rich gas, CO2-absorber, GOX expansion, and regain of LOX. The inert components will be discharged to the atmosphere downstream of the latter expansion along with remaining GOX (these sections are not depicted in the
The embodiment (III) of present patent in continuation presents the specific features of the CO2-Stream in pre-combustion carbon dioxide capture to obtain liquid carbon dioxide from the syngas generated from the gasification process, yet more specifically from the cathodic syngas of the HPLTE-SG of the parent patent, first in composition of CO/2H2, and then in CO2/3H2 composition downstream of the water shift converter(s).
The embodiment (III) includes also the pre-combustion carbon capture from the secondary CO2-Stream that stems from the carbon of the cathodic CO/2H2 stream downstream of the HPLTE-SG, and then through the HP or IP water shift converters. Thus the secondary CO2-Stream consists in CO2/3H2 composition (as disclosed in
This lean secondary CO2-Stream in turn, originates either downstream of the HPLTE-SG through the HP water shift converter (i.e. stream 37 in the
The points in reference to the CO2-Stream in the embodiment (III) for pre-combustion carbon capture from the gasification process or HPLTE-SG are interconnected with:
The present patent in continuation implies the peculiarities of the present process invention with regard to CO2-Stream treatment from the syngas by removal of CO2 from the syngas that considers the proceeding with the co-absorbed carbon monoxide, fine purification of CO2-Stream containing CO2 and carbon monoxide from the undesired traces of water and selexol in that stream, which takes place in the scavenger adsorber column, then the separation of carbon dioxide by liquefaction of carbon dioxide from CO2/CO/H2 gas stream in the parent patent's CO2-CC section, by then the rerouting of the offgas from the CO2-CC section consisting primarily of carbon monoxide with minor portion of carbon dioxide back to the syngas proceeding. These peculiarities are summarized as follows:
The specifics of the embodiment (III) is described more extensively via the
The CO2-Stream 1 can be compressed (it equals the element 7 in
If the syngas stems from HPLTE-SG with the following water shift converters, then the stream 7 consists of hydrogen alone for chemicals like NH3 or as it is considered for the super-efficient hydrogen based fossil power generation via Second Bairamijamal Cycle (
The absorbed carbon dioxide of the CO2-Stream 3 with the co-absorbed carbon monoxide in the selexol can be preferably preheated through the heat exchanger 17 before splitting in two streams 4, one for selexol rough regeneration by use of flash desorption in the flash drum 19 only. The other side dstream from 4 is processed to regeneration via (i) flash desorption 18, and then the (ii) thermal desorption 6. The fine regeneration of the selexol 6 from the flash desorption 18 is then preheated through the heat exchanger 20, by then regenerated in the thermal desorption column 21. The desorption gases, i.e CO2-rich/containing CO in lesser portion from the flash drums 18 and 19, are converge with the CO2-rich/CO containing desorption gas 10 from the thermal desorption column 21 are all routed together in the stream 11 for the fine purification of the CO2-rich/CO-containing gas through the scavenger adsorption column 22.
The treated CO2-enriched purified CO2-Stream 12 can be routed now to the parent patent's CO2-CC section, wherein the CO2 is separated from the CO2/CO-gas stream 12 by way of liquefaction, whereas the liquid carbon dioxide 15 can be directed to the parent patent's HPLTE-SG section. The remaining CO-rich off gas 13 can be recompressed with 23 and rerouted back to the syngas proceeding through the stream 14. The none-condensing gases, particularly in the start up period, is vented by the stream 24.
The present embodiment presents a way to the utilization of the CO2-enriched flue gas to generate process heat by use of gasification reactions for the CO2-HR and CO2-PG sections. The parent patent's disclosure references the process heat generated by use of chemical gasification reactions that had been presented for superheating and/or supraheating of carbon dioxide to high temperature in the new First Thermodynamic Cycle as part of the CO2-HR section. That process heat positions the recovery of available thermal energy or generating of process heat, which eventually is to generate primarily AC power by use of supercritical CO2 turbine(s) in the CO2-PG section. With reference to the parent patent, that AC power was designated to either be dispatched to the grid or be converted to DC current for backing up the electrolysis in the HPLTE-SG section.
However, there were no further specific details disclosed in the parent patent regarding the kind of those process heat sources nor as regards to the gasification, which chemical gasification reactions were to be employed for process heat generation. The present embodiment discloses the kind of those process heat generations as process heat generated downstream of a gas turbine, i.e. the heat recovery section of a gas turbine (i.e. specifically a gas turbine combined cycle as an independent power island aside the boundary line of this process invention or specifically an auxiliary gas turbine combined cycle within the boundary of the present process patent) as well as the process heat generated by the chemical gasification reactions. The process heat generation by either of the three v.s. sources comprises in the present patent in continuation also the superheating, and/or re-superheating of the saturated steam gained from the adjacent syngas utilizing plant into the present high temperature process heat generation.
In this embodiment, a part of the CO2-enriched recirculated flue gas is harnessed to generate high temperature process heat by way of the single-stage gasification reaction (7) or by way of two-stage gasification with (7) and (8) combined.
2CH4+O2+CO2→3CO+3H2+H2O (7)
CH4+H2O CO+3H2 (8)
In actuality, the overall reaction (7) is consisting of two parallel gasification reactions. One is the endothermic reaction of methane and carbon dioxide to form syngas in the composition [2CO/2H2], also referred to as methane reforming, while the other is the exothermic gasification reaction of methane and oxygen to form [CO/H2/H2O].
The reaction (8) is the typical endothermic steam reforming reaction that is carried out by catalytic reaction under lesser mol stream of natural gas relatively to the mol steam stream of the steam in order to prevent the cocks formation on the catalyst's surface. Thus, the molar ratio of steam to methane is kept between 1.5 to 3.0 typically. In utmost all present-day syngas and hydrogen generating plants the two above reactions, i.e. the endothermic steam reforming, and then the partial oxidation reaction of methane with oxygen are carried out in two distinct reactors, i.e. the Primary Reformer and Secondary Reformer, respectively. If these two reactions were carried out in one reactor, yet in two compartments, then the reactor is referred as autothermal reformer.
The present embodiment employs the overall reaction (7) in a single-stage gasification reactor in order to attain high temperature process heat, typically between 850 Deg C. to 950 Deg C. that is then utilized to superheat, rather supraheat the carbon dioxide to high temperature, yet preventing the thermal decomposition of carbon dioxide at supraheated region, typically at higher than 1000 Deg C. Equally, the present embodiment uses the same high temperature process heat to generate superheated steam, preferably the saturated steam from the adjacent plant, wherein the generated syngas streams of the present process is fed to produce final products like methanol, ethanol, gasoline, aviation fuel, ammonia and other final products.
The catalytic reaction (8) is carried out in the present embodiment via a two-stage gasification reactor in a case to case option only. If the reaction (8) is to be considered (for instance to adjust the CO/H2 ratio of the export syngas to the adjacent plant), then this embodiment considers the reaction (8) in a way that the molar ratio of the produced water through the reaction (7) stands to the natural gas reaching in to the chamber for the catalytic reaction (
more specifically:
Wherein the differential n presents the mol stream of each component at different load of the plant in steady state mode of operation.
The gasification of portion of the CO2-enriched recirculated flue gas, particularly with other CO2-containing gaseous process media, opens a new inventive advantageous way, distinguished with the following poignant reasons:
The above turbines are utilized to drive compressors (i.e. compressor for the recirculated flue gas, natural gas and others) as well as to drive generators for the primary AC current that can be either dispatched to the grid, or rather converted to DC current for back-up supply line for the HPLTE-SG electrolysis.
The present embodiment references in the mass and energy balances to a carbon ratio that refers to the carbon mol stream of CO2, which is deployed to the above gasification reactor to the carbon mol stream of the entire CO2 from the Advanced Combustion. This embodiment employs a carbon ratio in the sense of this definition in the margin of 15% to nearly 25% for gasification typically.
Higher ratio of 25% for the gasification can be economically reasonable, if additional oxygen is available at a site, like if the generated syngas from the HPLTE-SG and/or from the gasification of CO2-enriched CO2-Stream is be used for the ammonia production. Since in this case an air separation unit is needed to supply the nitrogen from the air, the off spin of that air separation unit can provide additional oxygen that then might reason the higher CO2-enriched CO2-Stream to the gasification.
The present embodiment is described exemplarily via
The flue gas post flue gas oxyfueling and recirculation from the Advanced Combustion 1 according to the Table 1 is routed to the compression section of the CO2-CC section that consists of subcritical flue gas compressor 31, and supercritical compressor 33 with respect to the discharge pressure of the compressors to the critical pressure of the carbon dioxide. The flue gas is split downstream of the subcritical compressor 31, whereas a portion of the flue gas 3.2 is utilized for preheating and gasification, while the main stream 3.1 of the flue gas is cooled by the intercooler 32, before the cooled flue gas 2 is directed to the supercritical compression 33 and eventually routed to the CO2-CC section for cooling, dehydration, and separation of the carbon dioxide by way of condensation.
The CO2-Sidestream 4 from the purge gas stream downstream of the CO2-CC's condenser(s), typically positioning ca. 10% of the CO2-enriched flue gas to the CO2-CC section 3.1 and consisting of ca. 7.5 Vol % CO2; 92 Vol % O2 with the rest of inert gases (mostly carbon monoxide and nitrogen from the nitrogen constituent of the coal) at a pressure of ca. 75 bar and temperature of ca. 31 Deg C. This CO2-Sidestream has been passed through the CO2-HR heat exchangers (e.g. vs. steam condenser, and process heat exchanger), before it is further superheated by syngas heat exchanger 47 and directed to the expander turbine 34 that generates AC power by the attached generator, before it is joined at a pressure of 45 bar and temperature of ca. 40 Deg C. via stream 5 to the stream 3.2 for the gasification.
The other CO2-Sidestream, the Regasified-CO2 6, originally used as condensing media in the flue gas condensation by partial release of liquid CO2 (ca. 5% of the entire liquid CO2) from ca. 75 bar and 31 Deg C. to ca. 45 bar and 10 Deg C. is preheated in the CO2-HR for waste heat recovery and joins at ca. 75 Deg C. to the other CO2-Streams 3.2 and 5 forming the stream 7. The stream 7 is preheated by syngas process heat recovery heat exchanger 46 up to ca. 450 Deg C. in single-stage gasification or up to nearly 375 Deg C. in two-stage gasification. Depending on load and temperature gradients, an additional syngas process heat exchanger 49 (not depicted in the
The flue gas compressors 31 and 33 are driven typically by turbine 36 either by supercritical CO2 turbine 36.1 or by an attached steam turbine 36.2, which also runs the generator 37 for generation of AC power.
Traditionally, the natural gas 9 for the generation of additional process heat shall be compressed with 35 for the gasification. Like the flue gas compressors, the natural gas compressor 35 is driven by a turbine 38, i.e. either by supercritical CO2 turbine 38.1 or by an attached steam turbine 38.2, which also drives the generator 39 for generation of additional AC power.
A side stream of hydrogen 10 is routed to the compressed natural gas, before the hydrogenated natural gas is directed to the hydration reactor 51 to convert the sulfur constituents of the natural gas to H2S in the stream 11. The H2S and residue of hydrogen in the natural gas is further directed to desulfurization reactor 52, wherein the H2S is reacted with the ZnO pellets to ZnS and water. The desulfurized natural gas 12 is further divided to the natural gas main stream 13, and 14 in case the two-stage gasification is to be carried out, and also to a side stream 13.1 for the ignition of the gasifier during the start-up period (not depicted in the
The additional oxygen for the gasification is performed from the IP extraction of the anodic oxygen 15 from the HPLTE-SG streams post the CO2-HR sections for the closing trajectory of the CO2 First Thermodynamic Cycle and preheated by heat recovery vs. steam in the steam condenser, then further superheated vs syngas process heat exchanger 48 and preheated in 16 up to ca. 185 Deg C. before it is joined to the CO2-Stream 7, forming the stream 8 with ca. 380 Deg C. upstream of the gasifier 40. The oxygen side stream 16.1 for ignition of the gasifier during the ramp up period is not depicted in the
The reactants to the gasification 40 consists of oxygen-added carbon dioxide stream 8 and the natural gas 13, which react to syngas by the reaction (7) generating a high temperature process heat with the standards reaction enthalpy of 75 kJ/mol. This process heat is eventually released in the high temperature section of the gasifier 41 cladded with refractory material and internal recirculation flux before it is routed downwards through the reactor's central pipe 42 (typically installed for the autothermal gasifier with the static mixer elements for homogeneous mixing of the secondary natural gas 14) in order to redistribute in the reactor lower chamber 43 upstream of the integrated heat recovery section 50 with the reactor's heat exchanger tubes 44. The gasifier 40 is distinguished by the reforming catalyst placed inside of the tubes 44 in case the autothermal gasification is to be carried out with the accompanying endothermic steam reforming reaction (8).
The generated hot syngas in the gasifier is recollected in the compartment 45 before passing out as stream 17. The hot syngas 17 may passes through an outside installed heat exchanger 49 (not depicted in the
The core objectives of high temperature process heat generation through the gasification of carbon dioxide and methane with the oxygen, primarily from the HPLTE-SG, comprises in this embodiment the 50 integrated in the reactor, with the optionally 49 installed outside of the reactor, which are employed to reheat the available supercritical superheated carbon dioxide (for instance at 175 bar, downstream of regenerative heat exchangers, and/or the saturated steam from the adjacent plant (e.g. saturated steam from methanol plant, typically at 47 bar with at least 260 Deg C, at massive mass throughput) up to a temperature field of 650 to 850 Deg C upstream of each turbine.
These re-superheating measures can be carried out by gasification and/or in combination with the heat recovery section of an auxiliary gas turbine, and/or further backed-up with supplementary firing via natural gas and oxygen and/or H2/O2 torches, or with the present gasification or a combination thereof.
For these objectives, the above two working media 19 (i.e. 19.1 superheated CO2 to supercritical CO2 supraheating and/or 19.2 saturated steam from the adjacent plant, or the 53.1 supercritical CO2 turbine and the 53.2 steam turbine for syngas recompression) are reheated by 20 downstream of reactor 40 (optionally downstream of the 49 in addition) before these streams are directed to the turbines, or are exported to other purposes as 21.1 and 21.2 respectively.
Finally, as the superheated CO2 and superheated steam are not available at the start up period of the gasification and syngas downstream plants in the start-up time period, the import lines for supercritical CO2 22.1 and 22.2 for superheated steam (e.g. from the auxiliary gas turbine) are considered for running the turbines initially.
In addition, the steam flush lines 24 is considered to flush the natural gas lines and the gasifier in plant trip situations and during the shut-down period.
The present patent in continuation to U.S. Ser. No. 14/392,066 uses also some special technical expressions and terms. Other terms, not described below, have been marshaled in the parent patent, subpart for abbreviations, special technical expressions, and terms.
Advanced Combustion:
The processing pertaining to the CO2-Stream of the parent patent in the post-combustion carbon dioxide capture to accomplish the chemical oxidation of the fossil fuel in a way that the combustion no longer harnesses the air with the adverse concomitant nitrogen. This kind of processing implies in the present patent in continuation the use of recirculated clean flue gas with CO2 as major constituent and oxygen in the post-combustion carbon dioxide capture. The related processing in the present patent comprises also the preparation and enhancement of CO2 concentration in the post-combustion, which enables the extraction of a very CO2-rich gas at very low gas flow rate for further processing.
Primary Carbon Ratio:
The U.S. Ser. No. 14/392,066 discloses a process, wherein the carbon constituent of the fossil fuel prior or post the combustion is regained as liquid carbon dioxide first, by then, that carbon dioxide is converted to cathodic syngas CO/2H2 and anodic oxygen in high pressure low temperature electrochemical syngas generator HPLTE-SG.
The cathodic syngas as well as the anodic oxygen are further employed as condensing media for the closing of the First Bairamijamal Cycle (each stream repeatedly, vide
Thus, the ratio of the mass flow rate of carbon in the circulating CO2 in the First Bairamijamal Cycle to the mass flow rate of the carbon from the fossil fuel is of pivotal significance. With the consideration of three to four times expansions of the HPLTE-SG syngas (CO/2H2) and oxygen (3/2 O2) with their respective stochiometric ratios, the available primary carbon ratio can recover great part of the waste heat, yet not all of it (v.i. for secondary carbon ratio).
Since the mass flow rate of carbon of the fossil fuel to liquid carbon dioxide that is fed to HPLTE-SG relates to primary carbon mass stream, subsequently the generated cathodic syngas and anodic oxygen from the primary carbon are interlinked to the portion of carbon mass flow rate in the CO2 cycle for the closing trajectory. For this reason, the more carbon rich the fossil fuel (like petcoke and coal) the higher waste heat can be effectively recovered, ergo the higher carbon constituent of the fuel, the higher gross efficiency of the process in both perspectives, i.e. in terms of plant gross thermal efficiency from the energy balance as well as in terms of revenue from the additional electricity to the grid, more significantly the revenue yielded from the high end final products.
Secondary Carbon Ratio:
The secondary carbon ratio is defined as the mol, rather mass flow rate of carbon in the First Bairamijamal Cycle to that of carbon monoxide of the cathodic syngas (CO/2H2), then post water shift converter to carbon dioxide (CO2/3H2). The obtained liquid carbon dioxide downstream of the CO2-CC section can now contribute via additional units of HPLTE-SG to regain more cathodic syngas and anodic oxygen, which can now recover more waste heat. The additional stream of (CO2/3H2) downstream of water shift converters are termed secondary CO2-Stream that is subject to the third embodiment of present patent in continuation for its pre-combustion enhancement of carbon dioxide concentration of CO2-Stream (vide embodiment (III) and
The U.S. Ser. No. 14/392,066 discloses the high-pressure water-shift converter (elements 35 with related equipment) as well as the intermediary pressure water shift converter (elements 46 with related equipment) for total or partial conversion of the syngas from HPLTE-SG. By operation of the water shift converters, hydrogen (stream 70) and additional CO2-Stream (streams 37 and 48) is produced, from which liquid carbon dioxide is regained downstream of the CO2-CC sections as streams 38 and 49.
Either stream 38, and 49 can be redeployed to a HPLTE-SG that generates additional syngas and additional oxygen again, while both additional streams contributing to more waste heat recovery. This proceeding can be carried out only to the extent, as long as the waste heat recovery can economically back up the electrolysis and CO2-PG.
The deployment of any CO2-Stream(s) as presented in
The additional hydrogen and oxygen generated essentially from the waste heat in addition to the primary hydrogen and oxygen are pivotal for supporting:
Primary CO2-Stream:
Relates to the carbon of the CO2-Stream that stems from the carbon constituent of the fuel
Secondary CO2-Stream:
With reference to
The second way is related to the conversion of the cathodic IP syngas (CO/2H2) 43 downstream of syngas expander turbine 42 to the IP water shift converter 46, where an IP lean secondary CO2-Stream (CO2/3H2) 48 is prepared. Thus, the present patent in continuation in the embodiment (III) pertains in second way to the pre-combustion carbon capture from this IP CO2-Stream 48 that is routed to another CO2-CC section, wherefrom the secondary liquid CO2 is also obtained again.
The enhancement of CO2 concentration from either HP/IP lean secondary CO2-Stream to a CO2-rich CO2-Stream appertains to this patent in continuation in the embodiment (III) with the
The secondary oxygen, along with excess hydrogen, is also employed for the cell fuels feeding that generates DC current for the high-pressure electrolysis without any need for AC/DC converter. Through this backup DC line, the loss of electric energy by the AC/DC of ca. 12% to 15% can be reduced noticeably, while more AC can be dispatched to the grid. The secondary oxygen is further harnessed for production of some downstream final products e.g. nitric acid and other oxo-hydrocarbons.
Secondary Liquid CO2
The collection of the both streams 38 and 49 above, constitutes the secondary liquid carbon dioxide. The generation of secondary liquid CO2 and its re-electrolysis with water.
Secondary Cathodic Syngas
The secondary cathodic syngas CO/2H2 is produced by re-electrolysis of the secondary liquid CO2 with water in another HPLTE-SG units. Depending on remaining waste heat, the secondary syngas contributes to more to back-up the power for the electrolysis via the multi-stage syngas expander turbine and more hydrogen for super-efficient hydrogen-based fossil power plants.
Primary Anodic Oxygen:
Relates to the oxygen that is generated by the electrolysis from the primary CO2-Stream out of the carbon constituent of the fossil fuel. The ration of the primary carbon and primary oxygen is determined by the stochiometric ratio of 1 C to 3/2 O2.
Secondary Anodic Oxygen:
The associated additional oxygen generated from the redeployed carbon dioxide back to electrolysis, presents the secondary oxygen.
The secondary oxygen, or simply secondary oxygen is of few paramount interests in the present patents. The parent patent presents a procedure to produce additional hydrogen and oxygen if the cathodic syngas CO/2H2 undergoes a water shift converter with steam, whereas the CO2/3H2 is produced. This has been presented in the description and depicted in the
The secondary anodic oxygen enables the present process to compensate the oxygen deficit of 1 C to ½ O2 in the mass balance if low-carbon fuel like natural gas is combusted, e.g. in CHP or gas turbine, for the CO2-Stream. The additional oxygen from this stream is termed secondary oxygen (vide table Advanced Combustion applied for an existing gas turbine).
Auxiliary CO2-Streams
The auxiliary liquid and gaseous carbon dioxide streams are considered in the parent, as well in the patent in continuation for some purpose. In the followings, few auxiliary CO2-Streams are disclosed with short elaboration related thereto.
Auxiliary Injection CO2 for De-Superheating:
There are number of regenerative heat exchangers considered in the First Bairamijamal Cycle of the parent patent in position to exchange the residue heat of supercritical CO2 downstream of the CO2 turbine along the trajectory 6-7 in the
Respectively, the last regenerative heat exchangers operate somewhere between ca. 160 Deg F to 110 Deg F. From there on to the critical zone around the 88 Deg F, the injection of liquid auxiliary carbon dioxide is considered into the supercritical carbon dioxide as a measure for de-superheating. This position of the de-superheating CO2 is considered as Auxiliary Injection CO2 for De-superheating. The auxiliary injection CO2 is resupplied by secondary liquid CO2, outlined above.
The injection CO2 serves also as the “make-up CO2” to compensate the regular discharge of CO2 from the cycle. The other usage of injection of liquid carbon dioxide is for de-superheating purposes, as indicated in
Auxiliary CO2 in ACU:
The parent patent considers the ACU, Auxiliary Cooling Unit for the supercritical (as well as subcritical condensation upon certain conditions). If the CO2 is utilized as cooling and chiller media, the continuous resupply of that CO2 is also to be provided via secondary CO2-Stream over the secondary liquid CO2.
Regasified-CO2:
The liquid CO2 that has been utilized in the ACU as condensing media for the condensation of the CO2 out of the flue gas to the CO2-CC section. Thus, the Regasified-CO2 has been obtained by partial release of the liquid CO2 from the supercritical CO2 pressure down at ca. 32 Deg C. to ca. 45 bar at ca. 10 Deg C. This regasified CO2 stream is then harnessed for the gasification reaction rather than to more costly recompression and rerouting back to the CO2-CC section. Hence this, it is referred to as the Regasified-CO2.
CO2-Sidestreams:
The CO2 containing side-streams, which are either not economically advantageous to be rerouted back to the core line of the processing in the CO2-CC cooling and condensation (e.g. the Regasified-CO2 stream) or are not suitable from process economy are collectively referred to CO2-Sidestreams.
For reasons of overall process economy, i.e. scope of the investment for the equipment as well the operation costs, these CO2-Sidestreams are preferably deployed for process heat generation in the gasification. The present process utilizes these side streams for the gasification unit in order to generate more valuable syngas and also generation of additional process heat that eventually contributes to more DC back-up power supply to the HPLTE-SG units. The other reason is grounded on process media suitability, for instance the oxygen-rich CO2-containing purge gas at higher pressure level, which are suitable for syngas generation by use of gasification.
The integration of CO2-Sidestreams buttresses the persuasion of the Zero CO2 Fossil Energy principal while considering the best available processing from technical and economy feasibility.
The ratio of the CO2-Sidestreams, as well the portion of the recirculated CO2-rich flue gas are defined by the molar ratio to the origin process media, whence they are derived.
Gas Turbine Trippel-Combined Cycle:
A new generation of gas turbine combined cycle, whereas now the Brayton Cycle of the gas turbine with the new Advanced Combustion is combined with a heat recovery section that integrates the current water-steam cycle of the Rankin Cycle together with the First Bairamijamal Cycle operating with the carbon dioxide as working fluid. Based on estimates, the new gas turbine triple combined cycle can reach out to a gross efficiency of 80% to 85% with a GE 9HA Class gas turbine.
Compared with the most advanced gas turbine combined cycle with HRSG based on 9HA Class to 62.3%, the present patent in continuation presents a quantum leap in gross efficiency in the gas turbine power generation.
Dual-Combined Cycle Power Plants
The application of the Advanced Combustion that is integrated in a new fossil fuel fired power plant with coal, crude oil, biomass, waste carbonaceous material and the natural gas, which heat recovery section is consisting of a water-steam cycle according to the classic Rankin Cycle and includes section for the heat recovery with carbon dioxide as the working fluid according to the First Bairamijamal Cycle.
The present continuation patent relates to the parent patent U.S. Ser. No. 14/392,066, which has been associated with the PCT/EP2014/000443, and the WO 2014/127913 A3 that refers to the U.S. Provisional Patent Application 61/850,685 with the priority date of Feb. 21, 2013. The present process invention presents the undisclosed information in connection with the CO2-Stream that is more specified in the upstream processing to the CO2-Stream with respect to the pretreatment of that CO2-Stream in order to derive a CO2-enriched CO2-Stream for the downstream section CO2-CC of the said patent, i.e. for compression, cooling of CO2-Stream and separation of the carbon dioxide from the CO2-enriched CO2-Stream to obtain liquid carbon dioxide by condensation of CO2 in the parent patent. In connection with the enhancement in the CO2 concentration of the CO2-Stream, there is also primary and secondary carbon ratio disclosed now that in turn is interlinked with the First Bairamijamal Cycle for waste heat recovery in the CO2-HR and power generation in the CO2-PG, yet more specifically in the closing path of the First Thermodynamic Cycle (the trajectories are depicted in FIGS. 4A, 5A and 5B). The figures of present patent in continuation are continued in numbering to the parent patent, i.e. FIGS. 11, 12 and 13. The claims of present patent in continuation are continued in numbering to the parent patent, i.e. with the following claims 61 to 76. The independent claims are 61, 62, 63, 68, 69, 70, 71 and 73. The dependent claims are 64, 65, 66, 67, 72, 74, 75 and 76.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14392066 | Aug 2015 | US |
| Child | 16820610 | US |
